颈动脉粥样硬化致血小板活化及其与急性脑梗死的关系

The Effects of Carotid Atherosclerosis on Activated Platelets and the Relation with Acute Cerebral Infarction

为探讨颈动脉粥样硬化致血小板活化机制及其与急性脑梗死的关系 ,采用彩色多普勒血流显像仪和流式细胞仪分别测定 115例急性脑梗死患者颈动脉及其周围血血小板表面CD6 2p、CD6 3的表达 ,并与 30例非脑梗死头晕患者对照。结果发现 ,急性脑梗死患者颈动脉粥样硬化斑块较对照组明显增多 ,单侧脑梗死者同侧颈动脉斑块明显增加 ,达 6 8.75 %,双侧脑梗死者双侧颈动脉斑块达 5 8.47%。斑块处狭窄 ,局部血流增快。颈动脉斑块患者血CD6 2p和CD6 3水平较正常动脉者明显增高 ,单侧颈内动脉粥样硬化斑块患者血CD6 2p和CD6 3的阳性率及荧光强度分别达 4.72 %± 4.5 2 %、5 .38%± 3.73%和 1.5 0± 0 .2 6、1.38± 0 .14,双侧斑块者达 7.72 %± 4.96 %、6 .78%±4.0 2 %和 1.5 9± 0 .37、1.41± 0 .18,后者较前者明显增高 (P <0 .0 5 )。脑梗死患者血小板活化率明显较对照组增高 ,并与颈动脉粥样硬化程度相关 (P <0 .0 5 )。结果提示 ,颈动脉粥样硬化构成“高剪切力 +低剪切力”的特殊剪切力梯度活化血小板 ,可能是颈动脉粥样硬化导致急性脑梗死的一个重要发病因素。

Aim To study the effects of carotid atherosclerosis on activated patelets and the relation with acute cerebral infarction. Methods Colour doppler flow imaging (CDFI) was used to assess carotid atherosclerosis and flow cytometry was employed to detect CD62p and CD63 expression on circulating platelet in 115 patients with acute cerebral infarction and 30 controls. Results The plaques of internal carotid artery (ICA) were significantly increased in patients with acute cerebral infarction than those in controls. 68.75% of left or right hemispheric infarctions was ipslateral to their plaques and 58.47% of the patients with bilateral hemispheric infarction had bilateral ICA plaques. The blood flow velocites were significantly increased in the throat of stenosis of ICA plaques. CD62p and CD63 expression on platelet were significantly higher in patients with ICA plaques than those in normal carotid controls, the positive percentages and fluorescence intensity of CD62p and CD63 were 4.72%±4.52%, 5.38%±3.73% and 1.50±0.26, 1.38±0.14 respectively in subjects with unilateral plaques and were 7.72%±4.96%, 6.78%±4.02% and 1.59±0.37, 1.41±0.18 respectively in subjects with bilateral plaques. Rates of platelet activation in the patients with brain infarction was higher than those in the controls and was related to the severity of carotid atherosclerosis. Conclusions The plaques of carotid atherosclerosis result in the complex patterns of high wall shear stress followed by low wall shear stress. Circulating platelets can be activated under the complex patterns of shear stress, which surgests shear-inducd platelet activation might play a pathogenetic role in onset of acute cerebral infarction.